Process for preparing thiophosphoric, thiophosphonic, and thiophosphinic acid esters



United States Patent 3,156,718 PROCESS 1 0R PREPARRNG THIGPHOSPHGRIC,THEUPHOSHONIQ AND THIGPHQSPHlNIC ACID ESTERS Walter Lorenz,Wuppertal-Vohwinkel, and Gerhard Schrader, Wuppertal-Cronenberg,Germany, assignors to Farbenfahrilren Bayer Alrtiengesellschatt,Leverluisen,

Germany, a corporation of Germany No Drawing. Continuation oiapplication 103,192, Apr. 17, 1961. 1962, Ser. No. 239,361

Claims priority, application Germany Apr.

Claims. ((11. zen-4&1)

R R and R are organic radicals.

This reaction is the object of copending application Serial No. 88,027,now U.S. 3,035,082, filed February 9, 1961.

During further investigation of this reaction and in accordance withthis invention it was found that, in general, salts of thiosulfonic acidmonoesters react with salts of phosphites, thiolphosphites,phosphonites, thicphosphonites, phosphinites and thiolphosphinites so asto form thiolesters of phosphoric acid, phosphonic acid, or phosphinicacid or their thiono-analogues respectively. The following generalequation may illustrate this: R1\O(S) R1 0(8) R2 B2 In these formulae Rand R denote alkoxy groups, aliphatic or aromatic residues; R and R maybe the same or ditferent; R denotes an optionally substituted, alkyl oraralkyl residue; Me denotes a univalent metal residue, particularly analkali metal or the ammonium radical.

The above described new reaction already takes place at roomtemperature, and generally proceeds exothermically. It is not necessaryto start from the alkali salts of the phosphites, phosphonites orphosphinites, but rather these salts may be formed during the reaction,by adding acid-binding agents. Solvents and diluents which have provedparticularly suitable for carrying out the reaction are those with astrongly polar character, such as, e.g., alcohols or even water.

The reaction as described is capable of being widely employed, so thatalso a large number of previously unknown phosphoric, phosphonic andphosphinic acid thiolesters can be obtained. Known compounds moreovermay be prepared in an easy and economical way.

The following examples may illustrate the present invention.

Ser. No. This application Nov. 21,

s II

Example 1 0 con.

OOH-

- s rens Ice Patented Nov. 1 9 1964 224 grams (1 mol) of2-ethylmercaptoethyl-thiosultonic acid sodium salt and 132 grams (1.2mols) of dimethyl phosphite are dissolved in 224 ml. of methanol. Afteraddition of 500 ml. of benzene, the amount of sodium methylatecorresponding to 1.25 mols of sodium is added dropwise at 0-5 C. duringthe course of 1 hour. After introduction of the calculated amount ofsodium methylate, the reaction product has a practically neutralreaction. The separated sodium sulfite is dissolved with 1.5 litres ofwater and separated, the product is washed neutral with a little water,dried over sodium sulfate, and the solvent is distilled off. There areobtained 114 grams of the ester-as a pale yellow, almost odorless oilwhich exhibits a boiling point of 76 C./0.0l mm. Hg; 11 1.5081. Yield49.5% of the theoretical.

Calculated for molecular weight 230.3: S, 27.84%; P, 13.45%. Found: S,28.81%; P, 12.98%.

Example 2 O OOH:

OGH

125 grams (1 mol) of 2-ethylmercaptoethyl chloride and 257 grams (1:04mols) of sodium thiosulfate are warmed to 70 C. in 160 ml. of water and160 ml. of methanol for 15 minutes. After a short while, the ethylchloride dissolves whilst sodium chloride separates. The solution iscooled to 0-5 C., 132 grams (1.2 mols) of dimethylphosphite and 500 ml.of benzene or methylene chloride are added, and a solution of 1.25 molsof caustic soda in 150 ml. of water is added dropwise at thistemperature. At the end, the solution is just alkaline towardsphenolphthalein. It is stirred at room temperature for another 30minutes, the sodium sulfite is filtered oh" by suction and separated,the product is washed neutral with Water, and dried over sodium sulfate.After the solvent has been distilled off, there are obtained 87.5 gramsof the ester as an almost colorless oil. H 1.5085. Yield 38% of thetheoretical.

Example 3 OCH 68 grams (0.3 mol) of 2-ethylmercaptoethyl-thiosulfonicacid sodium salt and 37 grams (0.33 mol) of dimethylphosphite aredissolved in ml. of water, and the solution is treated with a few dropsof phenolphthalein solution. After the addition of 250 ml. of benzene, asolution of 13.5 grams of caustic soda in ml. of water is added dropwisewith cooling so that the temperature is maintained at 5-10 C. Thesolution is weakly alkaline to phenolphthalein. The mixture is stirredat room temperature for another 30 minutes, the sodium sulfite isfiltered oil by suction and separated, the product is washed neutralwith water, dried over sodium sulfate, and the solvent is distilled off.By this method, there are obtained 24 grams of the ester, as a colorlessand odorless oil which distils at 7072 C. under a pressure of 0.01 mm.Hg; 11 1.5087. Yield 35.7% of the theoretical.

Calculated for molecular weight 230.3: S, 27.84%; P, 13.45%. Found: 8,28.52%; P, 13.03%.

Example 4 O OCzHs H/ CgH5SCHg-OE[z-SP OC H 68 grams (0.3 mol) of2-ethylmercaptoethyl-thiosulfonic acid sodium salt are dissolved in 150ml. of methanol and treated with 46 grams (0.33 mol) of diethylphosphite. The amount of sodium ethylate corresponding to 0.33 mol ofsodium is added dropwise at 5-10 C. whilst cooling with ice-Water.Sodium sulfite already separates at the beginning, and at the end of thesolution sets solid to a salt pulp. 250 ml. of benzene are added, andthe salts are dissolved in 1 litre of water. After separation, thebenzene solution is dried with sodium sulfate, and the solvent isdistilled By this method, 30 grams of the ester are obtained as apractically colorless oil. Yield 38.8% of the theoretical.

Example 4a 45 grams (0.33 mol) of 0,0-diethylphosphorous acid are addeddropwise to a solution of 74 grams (0.33 mol) of sodium2-ethylmercaptoethyl-thiosulfate in 150 cc. of Water, the mixture isthereafter cooled to C. and treated dropwise at 10l5 C. whilst coolingwith 42 grams (0.4 mol) of triethylarnine. After the addition has beencompleted, external cooling is removed, and the reaction mixture is leftalone for an hour to complete the reaction. During this process, thetemperature of the mixture slowly rises to 25 C. and the reactionproduct separates in the form of an oil at that time. The mixture isneutralized to a pH value of 6, and it is repeatedly extracted withmethylene chloride. After drying the methylene chloride solution oversodium sulfate, the solvent is distilled off. There is obtained the 0,0-diethyl S 2 (ethylmercaptoethyl)-thiolphosphoric acid ester as acolorless oil. [2 1.5088. Yield: 82 grams,

corresponding to 96.4% of the theoretical.

OCzH 68 grams (0.3 mol) of 2-ethyln1ercaptoethyl-thiosulfonic acidsodium salt are dissolved in 150 ml. of water. After the addition of 46grams (0.33 mol) of diethyl phosphite and a few drops of phenolphthaleinsolution, 13.5 grams (0.33 mol) of caustic soda, dissolved in 110 ml. ofwater (3 N alkali) are added dropwise at 510 C. during the course of2030 minutes. Towards the end of the addition of alkali, the reactionsolution just remains alkaline to phenolphthalein. It is stirred foranother 30 minutes at room temperature, the precipitated sodium suhiteis altered off by suction from the solution, and the salts are washedwith 250 ml. of benzene. The benzene layer of the filtrate is separated,Washed neutral with Water, dried with sodium sulfate, and distilled. 36grams of the ester are obtained as the residue. 12 1.4958. Yield: 48% ofthe theoretical.

Example 6 S OCHs ll/ c 115sOH2OI-n-s1 OCHs 68 grams (0.3 mol) of thesodium salt of Z-ethylmercaptoethyl-thiosulfonic acid are dissolved in150 ml. of methanol. 38 grams (0.3 mol) of dimethyl thiolphosphite and afew drops of phenolphthalein are added, and thereafter a solution ofsodium methylate containing 0.33 mol of dissolved sodium is addeddropwise at 510 C. The reaction product remains Weakly red colored atthe end. After stirring at room temperature for half an hour, water isadded until the salts have dissolved. The separated oil is taken up inbenzene, Washed neutral with Water, dried over sodium sulfate, and thesolvent is distilled off. 60 grams of the ester are obtained. 11;,1.5367. Yield 81.2% of the theoretical. The ester is an almost colorlessoil insoluble in Water.

4. Example 6a s (OI"I30)zl SCI-Ig-CIIgSC HE 74 grams (0.33 mol) of thesodium salt of 2-ethylmereaptoethyl-thiosulfuric acid are dissolved in150 cc. of water. After addition of 38 grams (0.3 mol) of 0,0-dimethyl-thiolphosphorous acid, 42 grams of triethylamine are addeddropwise to the resulting solution at 1020' C. whereupon a stronglyexothermic reaction sets in. Thereafter, the reaction mixture is stirredat room temperature for another half hour, the separated oil is thentaken up in benzene, and the benzene solution is Washed with water untilthere is a neutral reaction, dried over sodium sulfate, and distilled.After evaporation of the solvent, there is obtained the0,0-dimethyl-S-2-(ethylmercaptoethyl)-thionothiolphosphoric acid esterin the form of a colorless oil of 13.1. 71 C./0.01 mm. Hg. 12 1.5484.Yield: 63 grams, corresponding to 85.4%

the theoretical.

Example 7 S OC21'I5 As was described in the previous Example 6, 68 grams(0.3 mol) of 2-ethylmercaptoethyl-thiosulfonic acid sodium salt in 150ml. of methanol and 47 grams (0.3 mol) of diethyl thioiphosphite arebrought to reaction with a solution of sodium ethylate containing 0.33mol of dissolved sodium. After working up as usual, there are obtained72 grams of the ester as a colorless, odorless oil. n 1.5327. Yield:87.8% of the theoretical.

Example 8 O CgHs 37.5 grams (0.3 mol) of Z-ethylmercaptoethyl chlorideand 77.1 grams (0.31 mol) of sodium thiosulfate are warmed to C. in 50ml. of water and 50 ml. of alcohol for 10 minutes. Thereafter, it iscooled to 510 C., 46.2 grams (0.3 mol) of diethyl thiolphosphite and afew drops of phenolphthalein solution are added, and a solution of 13.5grams (0.33 mol) of caustic soda in 110 ml. of water is added dropwise,with stirring, until there is a color change. After the addition of 250ml. of benzene, sodium sulfite is filtered off by suction, the benzenesolution is washed neutral, dried over sodium sulfate, and the solventis distilled off. There are obtained 76 grams of the ester as acolorless and practically odorless oil. 11 1.5304. Yield 87.5% of thetheoretical.

Example 9 S OC H O CgHs 68 grams (0.3 mol) of benzyl-thiosulfonic acidsodium salt are suspended in 300 ml. of benzene. After the addition of51 grams (0.33 mol) of diethyl thiolphosphite, the amount of sodiummethylate corresponding to 0.33 mol of sodium is added dropwise at 2530C., with occasional cooling. The mixture is after-stirred for a shortwhile, Water is added, and it is separated. The benzene solution iswashed neutral with Water, dried over sodium sulfate, and distilled.B.P. C./0.01 mm. Hg. Yield 61 grams (73% of the theoretical).

Example I 0 OCH;

OCH;

68 grams (0.3 mol) of benzyl-thiosulfonic acid sodium salt and 37 grams(0.33 mol) of dimethyl phosphite are dissolved in 150 ml. of methanol.The amount of sodium methylate corresponding to 0.33 mol of sodium isadded dropwise at -10 C. The reaction is exothermic. After the additionof 300 ml. of benzene, the product is washed with water, dried oversodium sulfate, and distilled. Bl. 89 C./0.01 mm. Hg. Yield 31 grams ofthe new product (5 6.3% of the theoretical).

Calculated for molecular weight 232.2: S, 13.81%; P, 13.34%. Found: S,13.84%; P, 13.29%.

Example 11 S OCH:

OCH

65 grams (0.3 mol) of the sodium salt of thiosulfonic acidmethylacetamide (MP. 100102 C.) are dissolved in 200 ml. of water. Afterthe addition of 38 grams (0.3 mol) of dimethyl thiolphosphite in 250 ml.of benzene and a few drops of phenolphthalein solution, the amout of 3 Nsodium hydroxide solution corresponding to 0.33 mol is added dropwise at5-10 C., by cooling with ice water, until the solution is no longerdecolorized. It is separated and washed with Water. The benzene solutionis dried over sodium sulfate, and the solvent is distilled off. Thedistillation residue sets solid and it is triturated with ice coldpetroleum ether. It is filtered off by suction and 35 grams of the esterare obtained with M.P. 52 C. Yield 50.8% of the theoretical.

Example 11a 65 grams (0.3 mol) of sodiumN-methylcarboxarnidomethylthiosulfate are dissolved in 200 cc. of water.After the addition of 38 grams (0.3 mol) of0,0-dimethyl-thiolphosphorous acid, 42.5 grams (0.4 mol) of 95%triethylamine are added dropwise at -20" C., with external cooling, tothe reaction mixture. Thereafter, the mixture is stirred for another 4hour, whereupon no discoloration of any kind occurs, then neutralized toa pH value of 6 at 10 to C. with dilute hydrochloric acid, and a seedcrystal is added if necessary; ter cooling the reaction mixture to 010C. the separated crystals are filtered off by suction, and theprecipitate covered, on the filter funnel, with a little ice cold water.The product filtered off by suction and still containing inorganic saltsis dissolved in methylene chloride. The insoluble components arefiltered off by suction, and methylene chloride is evaporated from thefiltrate. There remain 55 grams (80% of the theoretical) of the 0,0-dimethyl S (N methylcarboxamidomethyl) thionothiolphosphoric acid esterin the form of colorless crystals of M1. 45 C.

A solution of 74.5 grams (0.3 mol) of sodium thiosulfate and 37.4 grams(0.3 mol) of monochloroacetic acid methyl amide in 75 cc. of water isheated to 7 0-80 C. for 15 minutes. Upon cooling the mixture, the sodiumsalt of N-methylcarboxarnidomethyl thiosulfuric acid crystallizes outwhich is redissolved by the addition of cc. of Water. After the additionof 38 grams (0.3 mol) of 0,0-dimethyl-thiolphosphorous acid, 42.5 grams(0.4 mol) of 95% triethylamine are added to the reaction mixture at 10to 20 C. with external cooling whereby a discoloration takes place, andthe mixture is then cooled to 0-10 C. after 15 minutes. The crystallizedester and the likewise separated inorganicsalts are filtered off withsuction and covered on the filter with ice-cold water. After drying ofthe precipitate, it is dissolved in methylene chloride, the undissolvedinorganic salts are filtered off with suction, and the solvent isevaporated off from the filtrate. 55 grams of the theoretical) of0,0-dimethyl S (N methylcarboxamidomethyl) thionothiolphosphoric acidester are obtained in the form of a colorless crystalline powder of MP.45 C.

Example 12 S O C 11 OCgHs 67 grams (0.3 mol) of the sodium salt ofglycollic acid-ethyl ester-thiosulfate (Purgotti, G. 22 I, 424) aredissolved in ml. of Water. A solution of 47 grams (0.3 mol) of diethylthiolphosphite in 200 ml. of benzene is allowed to run into thissolution. After adding phenolphthalein as indicator, a solution of 13.5grams (0.33 mol) of caustic soda in ml. of water is added dropwise at5-10 C., with cooling, until the solution is no longer decolorized. Itis stirred at 5-10 C. for another 30 minutes, separated, and the benzenesolution is washed until neutral, dried and distilled. B.P. 77 C./0.0lmm. Hg. A colorless, almost odorless oil, is obtained. Yield 43 grams(52.6% of the theoretical).

Example 13 S OCHa OCH;

50 grams (0.3 mol) of ethyl-thiosulfonic acid sodium salt are dissolvedin 100 ml. of water. 38 grams (0.3 mol) of dimethyl thiolphosphite areallowed to run into this solution, and a few drops of phenolphthaleinsolution are added. A solution of 14 grams (0.33 mol) of caustic soda in110 ml. of water (3 N) is added dropwise at 5-10" C., while cooling,until there is a permanent red coloration. The oil is taken up inbenzene, washed with water, dried over sodium sulfate, and distilled.B.P. 79 C./2 mm. Hg. Yield 55 grams (82.5% of the theoretical).

Example 14 S OC2H5 OCgHs 81 grams (0.3 mol) of4-nitrobenzyl-thiosulfonic acid sodium salt (Ml 176 C., Soc. 95, 1726)and 47 grams (0.3 mol) of diethyl thiolphosplnte are suspended in 200ml. of methanol; 0.33 mol of a 3 N sodium hydroxide solution (14grams/110 ml. of water) are added dropwise at 510 C. with cooling. Themixture is stirred for another 10 minutes, water is added until theprecipitated sodium sulfite has dissolved, and slight impurities arefiltered off by suction. The oil is taken up in benzene, Washed neutralwith water, dried over sodium sulfate, and the solvent is distilled off.88 grams of the ester are obtained as the residue. 13.1. 152-153 C./0.01 mm. Hg. Reddish yellow oil. Yield 91.4% of the theoretical.

Example 15 S OCHz ll/ (GH OH-NHC O-GHz-S-P 71 grams (0.3 mol) of thecrude sodium salt of thiosulfonic acid isopropylacetamide are dissolvedin 200 ml. of Water. After addition of 38 grams (0.3 mol) of dimethylthiolphosphite and a few drops of phenolphthalein' solution, 0.3 mol ofa 3 N sodium hydroxide solution (13.5 grams/110 ml. of Water) are addeddropwise at 5l0 C., with cooling, until there is a permanent redcoloration.

- During this process, the ester already crystallizes as colorless,finesmall needles. After further stirring for a short while at 510 C.,it is filtered off by suction and washed With water. After drying, 51grams of the novel ester are obtained. M.P. 7778C. Yield 66.2% of thetheoretical.

Example 15a 74.5 grams (0.3 mol) of sodium thiosulfate are dissolvedtogether with 42.7 grams (0.3 mol) of monochloroaceticacid-isopropylamide in 200 cc. of water, and the mixture is warmed to7080 C. for 15 minutes. A homogeneous solution is already obtainedwithin a short time, and this is cooled to 20 C. and treated with 38grams (0.3 mol) of 0,0-dimethyl-thiolphosphorous acid. Thereafter, 42.5grams (0.4 mol) of triethylamine are added to the reaction mixture at arate such that a term perature of 30 C. is not exceeded. After stirringfor about one hour, a crystalline mass separates. The mixture is cooledto 10 C., neutralized with dilute hydrochloric acid to a pH value of 6,and the crystals are filtered off by suction and quickly rinsed withice-cold Water. The precipitate is dried, and thereafter dissolved inmethylene chloride. After the inorganic salts have been filtered off bysuction, the solvent is evaporated from the filtrate, and 63 grams (i.e.81.7% of the theoretical) of the 0,0-di methyl S (Nisopropylcarboxymethyl) thionothiolphosphoric acid ester of MP. 78 C.are obtained.

A solution of 44 grams (0.21 mol) of bromomalonicacid-bis-monomethylamide (MP. 164 3., cf. J. V. Backen, R. W. West, andM. A. Whiteley, Journal of the Chemical Society, VOl. 119 [1921, p.365]) and 52 grams (0.24 mol) of sodium thiosulfate in 300 cc. of wateris warmed to 70-80 C. for 15 minutes. Thereafter, the mixture is cooledto C. treated first with 25.2 grams (0.2 mol) of0,0-dimethyl-thiolphosphorous acid, and then dropwise, at 1020 C.,whilst cooling, with 28.2 grams (0.27 mol) of 95% triethylamine. The0,0-dimethyl S bis N methylcarboxamido) methylthionothiolphosphoric acidester already starts to crystallize during the dropwise addition of thetriethylamine. To complete the reaction, the reaction mixture is stirredat room temperature for about another half an hour longer, the crystalmass is then filtered oif by suction, the precipitate is Washed withWater, and dried in the air. The product is pure. MP. 139 C. Yield 49grams i.e. 86.2% of the theoretical.

Arzalysis.C H O N S P: Calculated for molecular Weight 286.3: N, 9.78%;S, 22.40%; P, 10.82%. Found: N, 9.80%; S, 22.19%; P, 10.46%.

Toxicity on rats per os (LD amounts to 250 mg./kg.

Example 17 CgHb S li e CH2C ONHCH; 021150 65 grams (0.3 mol) of thesodium salt of N-methylcarboxamidoethyl-thiosulfuric acid are dissolvedin 200 cc. of Water, and after the addition of 42 grams (0.3 mol) ofethyl-thiophosphonous acid-O-ethyl ester, this solution is treateddropwise at 10-15 0., Whilst cooling, with 41 grams (0.45 mol) of 95%triethylamine. To complete the reaction, the mixture is stirred foranother hour at C. then neutralized to a pH value of 6, and the reactionproduct is now extracted with benzene. After drying the benzene solutionover sodium sulfate and distilling of the solvent, theethylthionothiolphosphonic acid-O-ethyl- S-(N-methylcarboxamidomethyl)ester remains in the form of a colorless oil with 11 1.5474. Yield 55grams, corresponding to 72% of the theoretical.

Example 18 A solution of 104 grams (0.5 mol) of the sodium salt ofW-methylcarboxamidomethyl-thiosulfuric acid in 104 cc. of water iscooled to 10 C. Thereafter, 66 grams (0.6 mol) of0,0-dimethylphosphorous acid are quickly added at this temperature tothe reaction mixture, and thereupon 74 grams (0.7 mol) of triethylamineare added dropwise at 10-15 C., whilst cooling. After stirring at roomtemperature for three hours, the mixture is neutralized with dilutehydrochloric acid to a pH value of 6, and the separated mass of salts isfiltered oil by suction. The filtrate is extracted by portions with 500cc. of methylene chloride, and after drying the methylene chloridesolution over sodium sulfate, the solvent is distilled olf. There remain72 grams (67.6% of the theoretical) of0,0-dimethyl-S-(N-methylcarboxamidomethyl)-thiolphosphoric acid ester asa colorless, viscous water-soluble oil.

68 grams (0.3 mole) of Z-ethylrnercaptoethyl-thiosulfonic acid sodiumsalt are dissolved in 150 ml. of methanol. 42 grams (0.3 mol) ofO-ethyl-thiolethylphosphonous acid (3P. 3 rum/58 C.) are reacted vith asolution of sodium ethylate which contains 0.33 mol of dissolved sodium.The second solution is slowly added with cooling to the first solutionat about 5-10 C. After the addition of about 1 litre of Water (until theseparated salt has dissolved), the separated oil is taken up in benzene,the benzene solution is washed with water, dried over Na SO after theWater has been separated, and the solvent is finally distilled ofif invacuo. There is obtained a colorless and almost odorless oil of 13.1. 82C./0.01 mm. Hg. The yield amounts to 72.5% of the theoretical.

Example 20 68 grams (0.3 mol) of sodium benzylthiosulfate and 27 grams(0.33 mol) of dimethyl-phosphinous acid are dissolved in 150 ml. ofmethanol. A solution of sodium methylate corresponding to a content of0.33 mol of sodium is added dropwise at 5 to 10 C. The reaction mixtureis diluted with benzene and then washed neutral with Water. After dryingover sodium sulfate, the residue is distilled in vacuo. There areobtained 17 grams of the above ester, With B.P. 82 C./0.01 mm. Hg.

Example 21 After the addition of 25 grams (0.32 mol) ofdimethylphosphinous acid (B.P. 42 C./l mm. Hg), 13.5 grams of causticsoda (0.33 mol) dissolved in cc. of Water are added dropWise at 5-10 C.to a solution of 68 grams 0.3 mol) of sodiumZ-ethylmercapto-ethyl-thiosulfate in ml. of Water. After the additionhas been completed, the reaction mixture is stirred at room temperaturefor another 30 minutes, the salts formed are then filtered off bysuction, and rinsed with 250 ml. of benzene. The benzene solution isseparated, dried with sodium sulfate, and fractionally distilled. Bythis method, there are obtained 55 grams (89% of the theoretical) ofdimethylthiolphosphinic acid-S -(fl-ethylmercaptoethyl ester of B1. 83C./0.01

at mm 9 We claim: 1. A process for the production of a compound of thegeneral formula in which R and R have the same meaning as given aboveand X is an alkali-forming group selected from the group consisting ofsodium, potassium and ammonium with a compound of the formula in which Xand R have the same meaning as stated above.

2. The process of claim 1 wherein R and R are each lower alkoxy.

3. The process of claim 1 wherein R and R are each lower alkyl.

4. The process of claim 1 wherein R is lower alkoxy and R is loweralkyl.

5. A process for the production of a compound of the general formula inwhich R and R are selected from the group consisting of lower alkyl andlower alkoxy and R is a member of the group consisting of lower alkyl,benzyl, nitrobenzyl, alkylmercaptoalkyl, alkylamidocarbonylalkyl andalkoXycarbonylalkyl, which comprises reacting an alkali salt of athiono-phosphorus acid of the formula in which R and R have the samemeaning as given above and X is an alkali-forming group selected fromthe group consisting of sodium, potassium and ammonium with a compoundof the formula in which X and R have the same meaning as stated above.

6. The process of claim 1 wherein the alkali salt of a phosphorus acidis formed in situ by reacting the corresponding thiono-phosphorus acidwith a member selected from the group consisting of sodium methylate,sodium ethylate, sodium hydroxide and triethylamine.

7. The process of claim 1 in which the reaction is carried out in asolvent selected from the group consisting of an aliphatic alcohol andwater.

8. The process of claim 6 in which the reaction is carried out in asolvent selected from the group consisting of an aliphatic alcohol andwater.

9. A process for the production of a compound of the general formula inwhich R and R are each selected from the group consisting of lower alkyland lower alkoxy, which comprises reacting an alkali salt of a compoundof the formula in which R and R have the same meaning as given above andX is an alkali forming group selected from the group consisting ofsodium, potassium and ammonium with a compound of the formula in which Xhas the same meaning as given above.

10. A process for the production of a compound of the general formula inwhich R and R are each selected from the group consisting of lower alkyland lower alkoxy, which comprises reacting an alkali salt of a compoundof the formula in which R and R have the same meaning as given above andX is an alkali forming group selected from the group consisting ofsodium, potassium and ammonium with a compound of the formula in which Xhas the same meaning as given above.

References Cited in the file of this patent Michalski et al.: J. Chem.Soc. (April 1960), pp. 1665-1670.

1. A PROCESS FOR THE PRODUCITON OF A COMPOUND OF THE GENERAL FORMULA 